You don't even have to modify the paper often. All that's really needed is for observers from any interested party to be allowed, which they are in the US. Then

You don't even have to modify the paper often. All that's really needed is for observers from any interested party to be allowed, which they are in the US. Then to affect anything above the city level an attacker has to bribe or coerce hundreds of people to turn a blind eye to things against their own political interests. They can watch polling places to spot ballot stuffing and counting places to spot count issues/fraud.